With the previously known three-dimensional vascular representation, a so-called mask run and a filler run are recorded. With the “mask run”, the C-arm of the C-arm x-ray apparatus rotates about the body part of the patient or the entire patient and records a first sequence of x-ray images (2D projection image data records) through the predetermined angular range without contrasting. Contrast agent is then injected into the vessel of interest and a second sequence of x-ray images is recorded with a renewed C-arm rotation, the so-called “filler run”. The two sequences are now subtracted from one another such that only the contrasted vessels (i.e. containing contrast agent) are still visible in the result. These are now reconstructed using a 3D reconstruction method to form a three-dimensional image data record. Alternatively, mask and filler run sequences can also be reconstructed separately from one another and the resulting three-dimensional data records can be subtracted from one another. Both the mask run and also the filler run are subsequently referred to as “rotation run”. With a rotation run for recording a 3D image data record, 120 to 140 projection image data records are usually recorded in each instance through a rotation angle of 200° of the C-arm of the C-arm x-ray apparatus as raw data and reconstructed to form a 3D image data record.
Here the recording of the projection image data records of a 3D image data record requires approximately 4 to 5 seconds, wherein the recording duration of the native 3D image data record is non-critical. The arterial phase of the contrast agent bolus, in other words the duration of stay of the contrast agent in the arterial vessels, is only however approximately 3 seconds. The contrast agent is subsequently transported via the capillary blood vessels into the veins. With the known recording method, it is therefore not possible to record sufficient projection image data records during the arterial phase in order to obtain separate, three-dimensional image data records of the arteries and the veins in each instance.
In order to solve this problem, DE 10 2006 012 181 A1 discloses implementing a number of rotation runs following the administration of a contrast agent in each instance, wherein the point in time of the administration of the contrast agent varies in comparison with the starting point in time of the recording data. Subsequently, those image data records recorded during the arterial phase from the recorded projection image data records for instance are selected in order to obtain a projection image data record for each required projection angle in order to be able to create a 3D image data record which was reconstructed from projection image data records, which represent the vascular system for the examined patient during the arterial phase. A three-dimensional image of the arteries of the patient is consequently obtained.
This method is disadvantageous in that a contrast agent has to be administered a number of times. Since the contrast agent remains in the vascular system throughout a time frame of several minutes, this may result, since it is increasingly distributed, in a deterioration of the contrast between a given contrast agent bolus and the fluid present in the vascular system.